Q38 of 269 Page 141

A solar cooker may not cook food if :

Glass sheet covers does not allow the solar energy to flow out in the form of radiant heat. Thus it traps more and more heat rays of the sun thereby producing green house effect. That is why glass lid are closed in the solar cooker in order to trap more and more heat.

More from this chapter

All 269 →
36

The minimum speed of wind necessary for the satisfactory working of a wind generator to produce electricity is about :

 37

If the solar constant is 1.4 kW/m2, then the solar energy received by 1 m2 area in one hour is :

 39

A large coal-fired power station producers 2000 MW of electrical energy. A wind turbine with 33 m blades can produces 300 kW.

(a) How many turbines would be needed to replace the power station?


(b) Why, in actual practice, this number of turbines could not replace the coal-fired power station?

 40

In a solar water heater, why is the storage tank placed at a higher level than the solar panel containing coils?